18 U.S.C. § 926 : US Code - Section 926: Rules and regulations

      (a) The Attorney General may prescribe only such rules and
    regulations as are necessary to carry out the provisions of this
    chapter, including - 
        (1) regulations providing that a person licensed under this
      chapter, when dealing with another person so licensed, shall
      provide such other licensed person a certified copy of this
      license;
        (2) regulations providing for the issuance, at a reasonable
      cost, to a person licensed under this chapter, of certified
      copies of his license for use as provided under regulations
      issued under paragraph (1) of this subsection; and
        (3) regulations providing for effective receipt and secure
      storage of firearms relinquished by or seized from persons
      described in subsection (d)(8) or (g)(8) of section 922.

    No such rule or regulation prescribed after the date of the
    enactment of the Firearms Owners' Protection Act may require that
    records required to be maintained under this chapter or any portion
    of the contents of such records, be recorded at or transferred to a
    facility owned, managed, or controlled by the United States or any
    State or any political subdivision thereof, nor that any system of
    registration of firearms, firearms owners, or firearms transactions
    or dispositions be established. Nothing in this section expands or
    restricts the Secretary's (!1) authority to inquire into the
    disposition of any firearm in the course of a criminal
    investigation.

      (b) The Attorney General shall give not less than ninety days
    public notice, and shall afford interested parties opportunity for
    hearing, before prescribing such rules and regulations.
      (c) The Attorney General shall not prescribe rules or regulations
    that require purchasers of black powder under the exemption
    provided in section 845(a)(5) of this title to complete affidavits
    or forms attesting to that exemption.